Latch reset filter unit

ABSTRACT

A filter unit that includes a slide assembly and a head assembly. The slide assembly is moveably mounted to the head assembly. The head assembly is configured to receive an end portion of a filter cartridge in releasable engagement. The slide assembly is movable between a first position in which the slide assembly prevents disengagement of the filter cartridge from the head assembly, and a second position in which the filter cartridge is permitted to disengage from the head assembly. In the second position, the slide assembly maintains engagement with the head assembly until an external force is applied by engagement of the filter cartridge with the slide assembly when removing the filter cartridge from the head assembly.

TECHNICAL FIELD

The present disclosure generally relates to filtering systems and moreparticularly relates to attachment features of a filtering system.

BACKGROUND

Water filtration systems designed for residential and commercial usehave become increasingly popular. The popularity arises from the need toremove unwanted substances from input water to make output water saferfor consumption in various end uses. Filter systems may also be used toadd substances to the output liquid, for example, minerals for tasteenhancement.

Different engagement mechanisms can be used to retain the filter mediain place until intentionally removed. During the course of use of waterfiltration systems, the filter itself can become particularly difficultto remove. When this occurs, the torque for removal or the “break outtorque” of the engagement mechanism for the filter media exceeds whatcan be expended by one-hand operation. Improvements in the engagementand latching mechanisms allowing for two-hand operation in thesesituations would be an advance in the art.

SUMMARY

One aspect of the present disclosure relates to a filter unit. Thefilter unit includes a slide assembly comprising an actuator and spring.The slide assembly is moveably attached and contained within a collarassembly. The collar assembly is configured to receive an end portion ofa filter cartridge in releasable engagement. The slide assembly ismovable between a first position in which the slide assembly preventsdisengagement of the filter cartridge from the collar assembly, and asecond position in which the filter cartridge can be disengaged from thecollar assembly. In the second position, the slide assembly engages thecollar assembly in a way that the second position is maintained until anexternal force is applied. The external force can result from engagementof a portion of the slide assembly with a portion of the filtercartridge as the filter cartridge is being disengaged from the collarassembly.

The above summary is not intended to describe each disclosed embodimentor every implementation of the inventive aspects disclosed herein.Figures of the detailed description that follow more particularlydescribe features that are examples of how certain inventive aspects maybe practiced. While certain embodiments are illustrated and described,it will be appreciated that the disclosure is not limited to suchembodiments or arrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of an example filter unit inaccordance with the principles of the present disclosure, the filterunit including a head assembly, a collar assembly, a slide assembly, anda filter cartridge;

FIG. 2 is a schematic perspective view of a first collar member of thecollar assembly shown in FIG. 1;

FIG. 3 is a schematic perspective view of a second collar member of thecollar assembly shown in FIG. 1;

FIG. 4 is a schematic perspective view of the slide assembly shown inFIG. 1;

FIG. 5 is a schematic perspective view of a portion of the filtercartridge shown in FIG. 1;

FIG. 6 is a side plan view of the filter unit shown in FIG. 1 with thehead assembly removed, the second collar member removed, and the slideassembly in a first unlatched position;

FIG. 7 is a schematic side view of the filter unit shown in FIG. 1 withthe head assembly removed, the second collar member removed, and theslide assembly in a first unlatched position and the filter is inposition to be installed;

FIG. 8 is another schematic side plan view of the filter unit shown inFIG. 1 with the head assembly removed, the second collar member removed,and the slide assembly in the first unlatched position and the filter isinstalled and locked;

FIG. 9 is a schematic side view of the filter unit shown in FIG. 1 withthe head assembly removed, the second collar member removed, and theslide assembly in second latched position allowing the filter to beuninstalled;

FIG. 10 is a schematic top view of the filter unit shown in FIG. 1 withthe head assembly removed, the second collar member removed, and theslide assembly in the first unlatched position;

FIG. 11 is a schematic top view of the filter unit shown in FIG. 1 withthe head assembly removed, the second collar member removed, and theslide assembly in the first latched position;

FIG. 12 is a schematic top view of the filter unit shown in FIG. 1 withthe head assembly removed, the second collar member removed, and theslide assembly returned to the first unlatched position; and

FIG. 13 is a schematic perspective view of another example filter unitwith the head assembly removed, the second collar member removed and thelatch protrusion positioned on the key ring.

DETAILED DESCRIPTION

Various embodiments will be described in detail with reference to thedrawings, wherein like reference numbers represent like parts inassemblies throughout the several views. Reference to variousembodiments does not limit the scope of the claims attached hereto.Additionally, any examples set forth in this specification are notintended to be limiting and merely set forth some of the many possibleembodiments for the appended claims.

The following discussion is intended to provide a brief, generaldescription of a suitable environment in which the invention may beimplemented. Although not required, the invention will be described inthe general context of a filter unit, for example, a filter unit forfiltering water for residential and commercial uses. The structure,creation, and use of some example filter units and methods are describedhereinafter.

The example embodiments disclosed herein have wide application to anumber of filter unit applications beyond the applications emphasizedherein. Features for releaseably securing two bodies together have manyapplications in a variety of environments outside of a filter cartridgeenvironment. While such alternative applications and environments arepossible, emphasis is placed on the application of features for a filterunit application, as that particular application is particularlybenefited from the embodiments described herein with reference to theattached figures.

The term “filter cartridge” as used herein, includes any deviceeffective for separating a feed (input) liquid-containing substance intoa product (output) liquid-containing substance of less undissolvedsolids and/or dissolved solids content than the feed liquid-containingsubstance and a filtrate or concentrate or permeate. The term “filtercartridge” includes a device that can add a substance to a feed (input)liquid-containing substance in the form of a modified product (output)liquid-containing substance. Thus non-limiting examples of filter meansas used herein include activated carbon filters, permeable sedimentfilters, water softeners, filters that add polyphosphates for scalecontrol, and reverse osmosis modules.

Some types of filter cartridges are maintained in an installedorientation relative to a mounting manifold or head assembly with sometype of engagement mechanism. Such engagement mechanisms resist rotationand/or axial movement of the filter cartridge relative to the manifoldunless the engagement mechanism is intentionally released. Thisresistance feature of such an engagement mechanism prevents theunintended release or removal of a filter, for example, under water linepressure. The amount of force required to remove a filter cartridge fromthe head assembly even when such an engagement mechanism is released canbe best applied when an operator can grasp the filter cartridge with twohands. The applied rotational torque required to remove a filtercartridge from the manifold is sometimes referred to as the “break outtorque.” If the engagement mechanism must be held in an actuated(disengaged) position in order to release the cartridge, it can bedifficult for the operator to maintain one hand releasing the engagementmechanism while using the other hand to apply the necessary break outtorque (e.g., rotating/twisting forces) to the filter cartridgenecessary to remove the filter cartridge from the head assembly.

The various filter unit examples described herein include a slideassembly that defines an engagement mechanism. The filter unit permitssecuring of the slide assembly in a latched configuration therebypermitting the operator to use two hands to grasp the filter cartridgewhen removing the filter cartridge from the manifold. Other aspects ofthe disclosed example filter units provides for automatic resetting ofthe slide assembly back into an unlatched position as part of theprocess of removing the filter cartridge from the manifold such that thehead assembly is not occupied by a filter cartridge and the headassembly is prepared to receive a replacement filter cartridge.

The disclosed examples illustrate a filter unit that includes aplurality of engagement features on each of the filter cartridge, acollar assembly, and a slide assembly supported in the collar assembly.Some of the slide assembly features are movable relative to the collarassembly and the filter cartridge in a rotation direction, a radiallyinward direction, and an axial direction relative to a central axis ofthe filter unit. The slide assembly can be positioned in unlatchedorientations as well as latched orientations. In each of the unlatchedand latched orientations, the slide assembly features are arranged toengage different portions of the collar assembly and filter cartridgeand or other components to provide the desired engagement functionality.

The Example Filter Unit Assembly of FIGS. 1-12

An example filter unit 5 is shown and described with reference to FIGS.1-12. The filter unit 5 includes a head assembly 11, a collar assembly12, a slide assembly 14, and a filter cartridge housing 16 (see FIG. 1).The slide assembly 14 is adjustably retained by the collar assembly 12.The slide assembly 14 can be removed from the collar assembly 12 byseparating first and second collar members 20, 22 of the collar assembly12. The head assembly 11 can be attached to a structural support, forexample, a wall or pipe. The head assembly 11 typically includes aninput 8 and an output 7. The input 8 and output 7 can be coupled influid communication to a water input line, a water output line, and aninterior of the filter cartridge 16. An example filter assembly thatincludes a filter housing and collar assembly is described in U.S. Pat.No. 4,915,831 (Taylor), which patent is incorporated herein byreference.

The collar assembly 12 includes first and second collar members 20, 22,a slide recess 24 and a spring recess 26 that are defined in each of thefirst and second collar members 20, 22 (see FIGS. 2 and 3), a firstlatch protrusion 28, first and second fasteners 30, 32 and a slide pivotrecess 34. The recesses 24, 26, 34 and protrusion 28 are configured tohouse or engage features of the slide assembly 14 as will be describedin further detail below.

The collar assembly 12 further includes key ring engagement trackfeature 36 adapted for engagement with key ring 74 and head trackengagement feature 37 for engagement with the head assembly 11.Typically, the collar assembly 12 is maintained in a fixed positionrelative to the head assembly 11. The filter cartridge 16 is secured tothe collar assembly 12 via the engagement of the filter cartridge 16with the ramp features 29

The first and second collar members 20, 22 include recess features 24,34 and protrusion features 26, 28 at one end thereof, and a mating setof recess features 25, 35 and protrusion feature 27 at an on oppositeend thereof. The recess features 24, 34 of the first collar member 20and the recess features 25, 35 of the second collar member 22 define acavity within which the slide assembly 14 is retained. The examplesillustrated herein include a single slide assembly 14 mounted to thecollar assembly 12. Other example configurations may include multipleslide assemblies 14 for each filter unit 5, depending upon the size andspatial need of the particular filter unit 5.

The slide assembly 14 includes a pivot member 40 having an engagementextension 41, a reset latch protrusion 42 extending from the pivotmember 40, a spring retaining member 44, a latch recess 46, anengagement surface 49, and a ramp surface 48 (see FIG. 4). The slideassembly 14 further includes an actuator 50 and a spring 52. The slideassembly 14 pivots about a pivot axis P1 that passes through the pivotmember 40 in a pivot unlatch direction P3 (see FIG. 11) and pivot latchdirection P4 (see FIG. 12). The pivot axis P1 is arranged at an angle131 relative to the XY plane as shown in FIG. 6. The pivot axis P1 isalso arranged parallel with the XZ plane (see FIG. 7).

The filter cartridge 16 includes a shoulder portion 60, a neck portion62, a first ramp member 64 positioned on the shoulder portion 60, and alug member 66 positioned on the neck portion 62 (see FIG. 5). The firstramp member 64 includes a shoulder portion 68. The lug member 66includes a neck stop surface 70. A plurality of keyed surface formations75 are also positioned on the neck portion 62. The key ring 74 isconfigured to engage the key ring engagement track feature 36 of thecollar assembly 12 to provide engagement of the filter cartridge 16 withthe collar assembly 12 via the mating keyed surface formations 75.

A spring axis P2 passes through the spring retaining member 44 (seeFIGS. 4, 6 and 7). Spring axis P2 is arranged at an angle β2 relative tothe XY plane (see FIG. 6), and at an angle β3 relative to the XZ plane(see FIG. 7). The spring 52 is captured between the spring retainingmember 44 and structure defining the spring recess 26 in the collarassembly 12. The spring 52 is oriented along the axis P2, therebyapplying a biasing force to the slide assembly in a direction defined byangles β2, β3. The direction of the applied biasing force helps retainthe slide assembly 14 in the first unlatched position C shown in FIG. 6prior to the first latch protrusion 28 engaging the latch recess 46 ofthe slide assembly 14. After the first latch protrusion 28 of the collarassembly 12 is engaged in the latch recess 46, the direction of thebiasing force applied by the spring 52 helps maintain engagement betweenthe first latch protrusion 28 and the latch recess 46 to maintain thefirst latched position F shown in FIG. 9.

The angle β1 is typically less than about 80°, more preferably about 40°to about 80°, and more preferably about 60° to about 80°. In somearrangements, the angle β1 could be a negative angle in the range ofabout 0° to about −80°.

The angle β2 is typically less than about 90°, more preferably about 40°to about 90°, and more preferably about 60° to about 80°. In somearrangements, the angle β2 could be a negative angle in the range ofabout 0° to about −90°. In some arrangements, the angle β2 is equal withβ1. The inherent flexibility of spring 52 permits unequal values forangles β1, β2 while still providing the desired biasing force tomaintain engagement between the latch recess 46 and first latchprotrusion 28.

The angle β3 is typically at least 15°. In some arrangements, the angleβ3 is in the range of about 0° to about 80°, and more preferably about15° to about 45°. In some arrangements, the angle β3 could be a negativeangle in the range of about 0° to about −90°.

Movement of the slide assembly 14 along the axis P1 between the firstunlatched position C shown in FIGS. 6, 8, and 12 and the second latchedposition shown in FIGS. 9 and 11 results in movement of the slideassembly 14 in each of the X, Y and Z directions relative to the collarassembly 12. Movement of the slide assembly 14 along the axis P1 changesa position of the reset protrusion 42 relative to engagement features ofthe filter cartridge 16 and changes a position of the latch recess 46relative to the latch protrusion 28 of the collar assembly 12.

The slide pivot recess 34 is arranged coaxial with the pivot axis P1that passes through pivot member 40. The pivot member 40 moves withinthe slide pivot recess 34, thus moving the slide assembly 14 in both theX and Z directions as the slide assembly 14 is moved between the firstunlatched position C and the second latched position F. As the slideassembly 14 moves along the pivot axis P1, the slide assembly 14 mustalso rotate in the pivot release direction P3 and pivot latch directionP4 about the pivot axis P1 due to engagement between the first latchprotrusion 28 (see FIG. 2) and the engagement surface 49 (see FIG. 4).Engagement of the first latch protrusion 28 with the engagement surface49 as the slide assembly 14 moves along the pivot axis P1, causes theslide assembly 14 to rotate about the axis P1 until the first latchprotrusion 28 engages within the latch recess 46 (see FIGS. 9 and 11).

An operator that actuates the slide assembly 14 from the first unlatchedposition C to the first latched position F engages the actuator 50 andapplies a force in the Z direction. Applying a force in the Z directionmoves the pivot member 40 along the pivot recess 34 at an angle β1. Asthe slide assembly 14 moves along the axis P1, the latch protrusion 28engages ramp surface 48 of the slide assembly 14, thus forcing the slideassembly 14 to rotate about the pivot axis P1 within the XY plane in therotation direction P3. At that point, the operator is actually applyinga force to the actuator 50 that has a component in each of the X, Y andZ directions. The operator continues to apply this force in the X, Y andZ directions until the first latch protrusion 28 is engaged within thelatch recess 46. In some instances, the operator must apply a rotationalforce in the P4 pivot direction when the slide assembly 14 has engaged atop surface of the latch recess 24 to ensure engagement of the firstlatch protrusion 28 in the latch recess 46 even though the biasing forceof the spring 52 tends to bias the slide assembly 14 in the pivot latchdirection P4.

Referring now to FIGS. 6-12, a method of retaining the filter cartridge16 engagement with the collar assembly 12 and slide assembly 14 isdescribed. A description of how the filter cartridge 16 is disengagedfrom the collar assembly 12 and slide assembly 14 is also provided.

Referring first to FIG. 6, the neck portion 62 of the filter cartridge16 is inserted in an axial direction into collar assembly 12 to initiateengagement between the key ring 74, the plurality of keyed surfaceformations 75 and ramp feature 29. Rotation of the filter cartridge 16in the engagement direction A (see FIG. 10) advances the filtercartridge 16 in the Z direction relative to the collar assembly 12.

Initially, the slide assembly 14 is in the first unlatched position C.Biasing forces applied by the spring 52 along the spring axis P2 tend tomaintain the slide assembly 14 in the first unlatched position C untilanother external force is applied to the slide assembly 14. FIG. 6illustrates the reset protrusion 42 of the slide assembly 14 spacedradially outward from engagement with the lug member 66 of the filtercartridge 16. In the first unlatched position C, the first latchprotrusion 28 is positioned vertically above (in the Z direction) theramp surface 48 and is not in engagement with the latch recess 46.

Referring now to FIG. 7, the filter cartridge 16 is rotated in theengagement direction A until the latch extension 41 of the pivot member40 of the slide assembly 14 engages the first ramp member 64 of thefilter cartridge 16. Engagement between the latch extension 41 and firstramp member 64 moves the slide assembly 14 in the XZ direction along theaxis P1 into the second unlatched position D. In the second unlatchedposition D, the first latch protrusion 28 engages with the ramp surface48, thus rotating the slide assembly 14 in the direction P3 about thepivot axis P1. The slide assembly 14 is not moved vertically in the Zdirection far enough for the first latch protrusion 28 to engage withinthe latch recess 46. Thus, after slightly further rotation of the filtercartridge 16 relative to the collar assembly 12 in the direction A, thelatch extension 41 moves over the first ramp member 64 and intoengagement with the shoulder 68 (see FIG. 8). The movement of slideassembly 14 in the Z direction into engagement with the shoulder 68 canoccur automatically under biasing forces applied by the spring 52.

Due to the offset positions of the first ramp member 64, and the lugmember 66 around a circumference of the filter cartridge 16, the secondlatch protrusion 42 can freely move in the X direction without engagingthe lug member 66 while the latch extension 41 moves over the first rampmember 64 and into engagement with the shoulder 68. With the latchextension 41 in engagement with the shoulder 68, the filter cartridge 16cannot be rotated in a disengagement direction B (see FIG. 10) todisengage the key rings 74 from the plurality of keyed surfaceformations 75 and to disengage the filter cartridge 16 from the collarassembly 12. In the position shown in FIG. 8, a lug member stop surface72 (see FIG. 5) contacts a collar stop surface 33 (see FIG. 3), therebylimiting further rotation of the filter cartridge 16 relative to thecollar assembly 12 in the engagement direction A. FIG. 10 is a top viewillustrating the latched orientation shown in FIG. 8, wherein the slideassembly 14 is in the first unlatched position C with the latchextension 41 is in engagement with the first ramp member 64 of thefilter cartridge 16.

Removing the filter cartridge 16 from the collar assembly 12 isinitiated by manually moving the slide assembly 14 along the pivot axisP1 in the XZ direction until reaching the third unlatched position E,wherein the slide assembly 14 is at the top end of the latch recess 24(see FIG. 9) and the first latch protrusion 28 is not engaged in thelatch recess 46. The third unlatched position can be maintained by onehand of the operator while a second hand of the operator is used torotate the filter cartridge 16 in the direction B to disengage the keyrings 74 from the key ring engagement track features 36 until the filtercartridge 16 is removed from the collar assembly 12.

Alternatively, the slide assembly 14 can be moved in the pivot directionP4 shown in FIG. 10 while the slide assembly 14 is in the thirdunlatched position E to engage the first latch protrusion 28 within thelatch recess 46 to establish the first latched position F shown in FIG.9. With the slide assembly 14 in the first latched position F, the latchextension 41 is positioned vertically above the first ramp member 64 inthe Z direction thereby permitting rotation of the filter cartridge 16relative to the collar assembly 12 in the direction B.

In some arrangements, the slide assembly 14 can maintain the firstlatched position F until the operator manually rotates the slideassembly 14 in the pivot release direction P3 to disengage the firstlatch protrusion 28 from the latch recess 46. Alternatively (as shown),the second reset protrusion 42 is provided on the slide assembly 14 toinitiate an automatic release of the slide assembly 14 from the firstlatched position F back into the first unlatched position C.

As shown in FIG. 9, the second reset protrusion 42 is positioned furtherradially inward in the X direction towards the filter cartridge 16 neckportion 62 as compared to the position of second latch protrusion 42when in the first unlatched position C shown in FIG. 6. Referring now toFIG. 11, while the slide assembly 14 is maintained in the first latchedposition F and the filter cartridge 16 is rotated in direction B, thesecond reset protrusion 42 engages the neck surface 70 of the lug member66. Still further rotation of the filter cartridge 16 in the direction Bapplies a force to the second reset protrusion 42 that rotates the slideassembly 14 about the pivot axis P1. This action causes the latch recess46 to rotate away from latch protrusion 28. Once the first latchprotrusion 28 is moved out of the latch recess 46, the biasing forcesapplied by spring 52 forces the slide assembly 14 back into the firstunlatched position C (see FIG. 12). With the slide assembly 14 in thefirst unlatched position C, the second latch protrusion 42 is movedradially outward in the X direction to disengage the second latchprotrusion 42 from the neck stop surface 70, thereby permitting furtherrotation of the filter cartridge 16 in the direction B until the filtercartridge 16 is removed from the collar assembly 12.

Movement of the slide assembly 14 along the axis P1 (e.g., from thefirst unlatched position C to the second unlatched position D) can beconsidered translational movement. Movement about axis P1 (e.g.,movement from the third unlatched position E to the latched position F)can be considered rotational movement. The slide assembly 14, when beingmoved between the first unlatched position C and the latched position Fexperiences both translational and rotational movement.

The slide assembly 14, having been automatically reset into the firstunlatched position C, is now prepared for receiving a replacement filtercartridge 16. If the slide assembly 14 were to remain in the latchedposition F, the second reset protrusion 42 would interfere with the neckstop surface 70 (see FIG. 9) when installing the replacement filterhousing thereby preventing installation of the replacement filtercartridge 16. The automatic reset features of the slide assembly 14 canbetter ensure that the consumer is able to properly install thereplacement filter housing. If the consumer inadvertently actuates slideassembly 14 into the latched position F after the filter cartridge 16has been removed, the second reset protrusion 42 would interfere withthe neck stop surface 70 (see FIG. 9). However, when the consumerremoves the filter cartridge 16 in direction B the automatic resetfeatures of the slide assembly are actuated and proper installation ofthe filter cartridge 16 is permitted.

The slide assembly 14 is configured to move primarily within the XZplane between the first unlatched position C and the latched position F.In other examples (not shown), the slide assembly 14 can be arranged tomove primarily in the YZ plane, in the XY plane, or any plane arrangedat angles relative to the XZ, YZ, and XY planes. Furthermore, theillustrated example provides for movement of the slide assembly 14 intothe latched position F by moving generally in the Z direction along theaxis P1 generally away from the filter cartridge 16. In otherarrangements, the slide assembly 14 can be arranged to move in anopposite direction generally towards the filter cartridge 16 to attainthe latched position F.

The slide assembly 14 is shown in the Figures mounted primarily to thecollar assembly 12 of the head assembly 11. In other arrangements, theslide assembly 14 can be mounted to other features of the head assembly11. Although the two-piece construction of the collar assembly 12provides some advantages in capturing the slide assembly 14 in a mountedposition in the head assembly 11, other constructions and arrangementare possible for the slide assembly 14 and head assembly 11 to permitmounting of the slide assembly 14 in different ways while providing thedesired latching functions. In still further arrangements, at least someaspects of the slide assembly 14 can be mounted to the filter cartridge16. In still further arrangements some aspects of the first ramp member64 (such as the shoulder stop portion 68) can be alternatively mountedon the key ring 74 while maintaining essentially the similar lockingfunction of the filter cartridge 16.

The Example Filter Unit Assembly of FIG. 13

The example filter unit assembly illustrated in FIGS. 1-12 has the stopsurface 70 on lug member 66. FIG. 13 illustrates another embodimentwhereby a stop surface 270 is on a key ring 274, replacing the stopsurface 70 described in the previous embodiment in FIGS. 1-12. The stopsurface 270 functions similar to the stop surface 70, wherein rotationof a filter cartridge 216 results in a second reset protrusion 242 of aslide assembly 214 engaging the stop surface 270. A primary differencebetween the stop surfaces 70, 270 is the location of the stop surface270 compared to the location of the stop surface 70.

Other embodiments of the present disclosure include filter units havingstop surfaces, reset protrusions, and other features described hereinused in conjunction with rotary valves, other valve members, and furtherfilter unit features that rotate with or without the filter cartridgewhen mounting a filter cartridge to a head assembly, such as thosefeatures described in U.S. Pat. No. 6,458,269 (Bassett et al.), which isincorporated herein by reference in its entirety.

CONCLUSION

One aspect of the present disclosure relates to a filter unit thatincludes a filter cartridge, a slide assembly, and a head assembly. Theslide assembly includes, a spring, and a first latching member. The headassembly includes a latch recess and a second latching member and isconfigured to receive a filter cartridge in releasable engagement. Thelatch recess is configured to receive at least a portion of the slideassembly, and the second latching member is configured to releaseablyengage the first latching member. The slide assembly is movable bytranslational and rotational movement between a latched position inwhich the first and second latching members are engaged and the filtercartridge is permitted to rotate relative to the head assembly, and aunlatched position wherein the first and second latching members aredisengaged and the slide assembly engages the filter cartridge to limitrotational movement of the filter cartridge relative to the headassembly. The latch assembly can further include a third reset member.The third latching member is arranged and configured to engage thefilter cartridge during rotation of the filter cartridge when the slideassembly is in the latched position. Engagement of the third latchingmember with the filter cartridge disengages the first and secondlatching members.

Another aspect of the present disclosure relates to a filter unit thatincludes a filter cartridge, a head assembly, and a slide assembly. Thehead assembly includes a first latching member. The slide assemblyincludes a second latching member. The filter cartridge is releaseablymounted to the head assembly. The slide assembly is configured to movebetween a first position in which the filter cartridge is held in afixed axial and rotational position relative to the head assembly, and asecond position in which the filter cartridge is moveable axially androtationally relative to the head assembly. The slide assembly is alsoconfigured to maintain the second position by engagement of the firstand second latching members until the slide assembly engages the filtercartridge at a predetermined rotated position of the filter cartridgerelative to the head assembly to disengage the first and second latchingmembers prior to removing the filter cartridge from engagement with thehead assembly.

A further aspect of the present disclosure relates to a method ofdetaching a filter cartridge from a filter cartridge head assembly. Thehead assembly includes a slide assembly and is movable between a latchedposition and an unlatched position. The filter cartridge includes firstand second stop members. The method includes moving the slide assemblyfrom the unlatched position wherein the slide assembly engages the firststop member to restrict rotation of the filter cartridge relative to thefilter cartridge head assembly, into the latched position in which theslide assembly is disengaged from the first stop member to permitrotation of the filter cartridge relative to the head assembly. Themethod also includes engaging a first latch member of the slide assemblywith a second latch member of the head assembly to retain the latchassembly in the latched position, rotating the filter cartridge in arelease direction relative to the head assembly until the second stopmember engages the slide assembly to disengage the first and secondlatch member to provide movement of the latch assembly from the latchedposition to the unlatched position, and further rotating the filtercartridge in the release direction until the filter cartridge is removedfrom the head assembly.

In the foregoing detailed description, various features are occasionallygrouped together in a single embodiment for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments of the subjectmatter require more features than are expressly recited in each claim.Rather, as the following claims reflect, inventive subject matter liesin less than all features of a single disclosed embodiment. Thus, thefollowing claims are hereby incorporated into the detailed description,with each claim standing on its own as a separate preferred embodiment.Therefore, the sphere and scope of the appended claims should not belimited to the description of the preferred versions contained herein.

1. A filter unit, comprising: a slide assembly, the slide assembly including a first latching member; and a head assembly, the head assembly including a latch recess and a second latching member, the head assembly configured to receive a filter cartridge in releasable engagement, the latch recess configured to receive at least a portion of the slide assembly, and the second latching member configured to releaseably engage the first latching member; wherein the slide assembly is movable by translational and rotational movement between a latched position in which the first and second latching members are engaged and the filter cartridge is permitted to rotate relative to the head assembly, and a unlatched position wherein the first and second latching members are disengaged and the slide assembly engages the filter cartridge to limit rotational movement of the filter cartridge relative to the head assembly.
 2. The filter unit of claim 1, wherein the slide assembly further includes a reset member, the reset member arranged and configured to engage a reset protrusion during rotation of the filter cartridge when the slide assembly is in the latched position, wherein engagement of the reset member with the reset protrusion disengages the first and second latching members.
 3. The filter unit of claim 1, wherein the slide assembly further includes a spring, the spring being arranged to bias the slide assembly into the unlatched position.
 4. The filter unit of claim 3, wherein the spring is configured to bias the first and second latching members into engagement with each other when the slide assembly is in the latched position.
 5. The filter unit of claim 3, wherein the slide assembly is movable with translational movement along a first axis, and the spring is arranged at an angle relative to the first axis.
 6. The filter unit of claim 1, wherein the first latching member is a recess and the second latching member is a protrusion.
 7. The filter unit of claim 2, wherein reset member is a protrusion.
 8. The filter unit of claim 1, wherein the head assembly includes a collar assembly, and the slide assembly is operatively mounted to the collar assembly.
 9. The filter unit of claim 2, wherein the reset protrusion is positioned on the filter cartridge.
 10. A filter unit, comprising: a filter cartridge; a head assembly including a first latching member; a slide assembly including a second latching member, the filter cartridge being releaseably mounted to the head assembly, the slide assembly being configured to move between a first position in which the filter cartridge is held in a fixed axial and rotational position relative to the head assembly, and a second position in which the filter cartridge is moveable axially and rotationally relative to the head assembly, the slide assembly being configured to maintain the second position by engagement of the first and second latching members until the slide assembly engages the filter cartridge at a predetermined rotated position of the filter cartridge relative to the head assembly to disengage the first and second latching members prior to removing the filter cartridge from engagement with the head assembly.
 11. The filter unit of claim 10, wherein the slide assembly further includes a reset member, the third latching member being arranged and configured to engage the filter cartridge at the predetermined rotated position.
 12. The filter unit of claim 10, wherein the slide assembly further includes a spring, the spring being arranged to bias the slide assembly into the second position.
 13. The filter unit of claim 10, wherein the slide assembly further includes a spring, and the spring is configured to bias the first and second latching members into engagement with each other when the slide assembly is in the first position.
 14. The filter unit of claim 10, wherein the first latching member is a recess and the second latching member is a protrusion.
 15. The filter unit of claim 11, wherein reset member is a protrusion.
 16. The filter unit of claim 15, wherein the filter cartridge includes a reset protrusion configured to engage the reset member at the predetermined rotated position.
 17. A method of detaching a filter cartridge from a filter cartridge head assembly, the head assembly including a slide assembly, the slide assembly being movable between a latched position and an unlatched position, the filter cartridge including a stop member and a reset protrusion, the method comprising: moving the slide assembly from the unlatched position wherein the slide assembly engages the stop member to restrict rotation of the filter cartridge relative to the head assembly, into the latched position in which the slide assembly is disengaged from the stop member to permit rotation of the filter cartridge relative to the head assembly; engaging a first latching member of the slide assembly with a second latching member of the head assembly to retain the slide assembly in the latched position; and rotating the filter cartridge in a release direction relative to the head assembly until the reset protrusion engages the slide assembly to disengage the first and second latching members to permit movement of the slide assembly from the latched position to the unlatched position; and further rotating the filter cartridge in the release direction until the filter cartridge is removed from the head assembly.
 18. The method of claim 17, wherein moving the slide assembly between the unlatched and latched positions requires translational and rotational movement.
 19. The method of claim 17, wherein the filter cartridge rotates about a first axis in the release direction, and the slide assembly moves along a second axis between the latched and unlatched positions, the first axis and the second axis being arranged non-parallel with each other.
 20. The method of claim 17, wherein the first latching member is one of a recess and a protrusion, and the second latching member is the other of the recess and the protrusion, and engaging the first and second latching members includes inserting the protrusion into the recess.
 21. The method of claim 20, wherein moving the protrusion out of the recess via rotational movement of the slide assembly relative to the head assembly permits translational movement of the slide assembly relative to the head assembly. 